So it looks like people who like light-medium revovating have another option here. Buying unfinished house than finish it adding value (saving on labour), getting occupation certificate and than rent it or sell it. 

Who is issuing occupancy certificate and is it possible to get occupancy inspection certifier (who?) twice. Once when handing over from builder to onwer/renovator investor and than from renovator/investor to new owner or same but ready for occupancy? 

How much does it cost?